Telephone instrument



Jung: 16,1925.Y l 1,542,377

. H. F. DOBBIN TELEPHONE INSTRUMENT Filed July 2Q.` 1923 Patented June 16, 1925.

PATENT OFFICE.

UNITED STATES HENRY F. DOBBIN, OFNEW YORK, N. Y., AssIGNOe fro WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., a oOaron-ATION or New YORK.

TELEPHONE INSTRUMENT.

' 1 Appucation ineaauly 2o,

To all whom 'it may concern.'

Be it known that I, HENRY F. DOBBIN, a citizen of the United HSta-tes, residing at New York, in the county of New York, State of New York, have invented certain ,new and useful Improvements in yTelephone Instruments, of which the following'is a full, clear, concise, and exact description.

rIhis invention relates to Atelephone substation apparatus, and its object is to provide a simple switching mechanism, therefor which will prevent vthe sending of false impulses and the causing of premature disconnections by incomplete movements of the switchhook in either direction.

In accordance with the features ofthe invention there is provided a switching mechanism comprising a member operated by the switchhook lever against the action of a restoring spring and operating the contact springs at a predetermined time in the switchhook movement through .the medium of a lost motion switching mechanism.

The drawing shows a telephone desk stand embodying the invention.

Fig. 1 is a side view of the desk stand with part of the covering removed t0 reveal the operating mechanism.

Fig. 2 is a bottom view of this mechanism. V

Fig. 3 is a front view of the switchhook and its associated mechanism.

Figs. 4, 4b and 4c showy the respective positions of the switchhook, the contact springs, and the spring operating lever when the switchhookis down; and Figs. 5a, 5b and 5C show the relative positions of these members when the switchhook is raised.

The desk stand comprises a stem 7 resting on a base 8 in which a calling dial 9 may be mounted. i A transmitter holding member 11 is set into stem 7 and the end of a switchhook 12 is rotatably attached thereto at 13. A vertical shaft 15 in the stem 7 is held against the shank of the switchhook 12 by a spring 16 attached to a terminal plate 17 set in the base 8. The lower portion of shaft r15 is threaded so thatthere may be screwed thereon a lostmotion device comprising an upper stop member such as nut 19 and a lower stop member such as nut 20. Between i these nuts is set a stud 22 whose thickness is somewhat less than the distance between the nuts. Stud 22 is attached to a lever 25 pivoted at 26 to an extension 27 of plate 17.

1923. Serial No. 652,755.

A stud 28 on the opposite'end of lever 25 from stud 22 bears against a contact spring 29 which forms a part of a bank 30. A sec- Aond spring 31 is distanced from spring 29 by a stud 32 and operates therewith. As

may be seen by referring to Figs. 4a' and Lil" maintain the lever and the springs in either Y the position shown 1n Figs. 4C and 1" or 1n f the positions shown in Figs. 5c and 5b until positive pressure is brought to bea-r on the stud22, al third stud 34 is attached to the lever 25 and bears against a spring 35 attached to terminal plate 17. In this spring are two corrugations 36 and 37 into one of which lstud 34 fits when the switchhook is raised and into the other of which the stud fits when the switchhook is down. This arrangement prevents the contacts from being opened or closedby a slight movement of the-switchhook to cause false impulses to be sent over to the line circuit. The spring 35 holds stud 311 in lever 25 firmly in place until the movement of the rswitchhook has caused the shaft 15 to be raised or lowered a distance equal to the distance between stud 22 and the nut farthest therefrom so that positive pressure is brought to bear on stud 22`to move lever 25 and stud 34 to make or break contact between the springs. Figs. 1a to 5c inclusive, serve to illustrate the manner in which this mechanism operates.

The threading of the lower end of shaft 15enables the easy adjustment of the lost motion mechanism so as to properly align stud 34 with the corrugations in spring 35.

The invention claimed is:

1. In a telephone instrument, a switchhook, a reciprocating shaft controlled by said switchhook., a member fixed to said shaft and carrying a pair of operating lugs, a lever disposed between said lugs so as to allow said shaft a certain amount of play in either direction without actuatingsaid lever and thereafter actuating said lever, and contact springs actuated by the movement of said lever.

2. In a telephone instrument, a switchhook, contact springs, aY shaft actuated by the switchhook, a lost motion mechanism on the shaft, and means controlled by said lost motion mechanism and comprising a ystud fearing against a corrugated spring member to cause the actuation of said contact 5 sn'inesb7 the latter aart of the switch* l s 5 l hook movement in either direction.

3. In a telephone instrument, a switchhook, Contact springs, a sha-ft actuated by the switclihook, a lost motion mechanism on 0 the shaft, a lever operated by 'the lost motion Cif switchhook having a limited movement, contact springs on the base, a vertical shaft, a lost motion mechanism adjustably mounted on the shaft, and a lever member operated by-thelost motion mechanism, astrid on said' lever to operate said contact springs, a flat spring member having` two corrugations therein, a second stud on said lever bearing against said spring` member and adapted to lit in one or the other of said corrugations,

said mechanism being` so arranged that Athe contact springs are actuated only-in response to the latter part of the switchhook morcment in either direction, and means yfor ad justine" said lost moticn mechanismA In Witness whereof, I hereunto subscribe my naine Vthis 17th day-offJfuly A. D. 1923.

HENRY F. DOBBIN. 

